A. A. Sivkov

Influence of the supplied energy on electroerosion recovery of material in an electrotechnical accelerator

The effect of the energy on the dynamics of electroerosive surface wear of the accelerating channel in a coaxial magnetic plasma accelerator is studied. The energy supplied to the accelerator is varied by cutting off the current pulse tail by a trigatron arrester at different instants of times. It has been ascertained that the dynamics of electroerosive surface wear of the accelerating channel is mainly determined by the behavior of the discharge power in the course of the process in the accelerator.

Plasmodynamic synthesis of nanocrystalline structures in the C-N system

The results of studies on the direct plasmodynamic synthesis of ultradispersed crystalline phases in the C-N system are presented. According to the data of X-ray diffraction analysis and electron microscopy, the product contains a phase close to the calculation model of carbon nitride αC3N4.

Studies of multiple and frequency operation of a coaxial magnetoplasma accelerator for production of superhard nanodispersed titanium compounds

It is demonstrated that a system based on coaxial magnetoplasma accelerator facilitates dynamic synthesis of nanodispersed titanium crystalline phases, such as cTiN and TiO2, during multiple use of a titanium barrel as a consumable material. The efficiency of material yield from the surface of the accelerating channel of a titanium barrel increases upon cyclic operation of an accelerator with duration of currentless pause less than 1.0 s.

Production of ultradispersed crystalline silicon carbide by plasmodynamic synthesis

The direct plasmodynamic synthesis of β-SiC ultradispersed cubic silicon carbide under the action of supersonic pulse flow of carbon-silicon electric-discharge plasma onto a copper barrier in the argon atmosphere has been realized. A powdered product with a high β-SiC content has been obtained, whose single crystals have a mean size of about 100 nm and natural crystallographic habit close to the ideal one.

Dynamic synthesis of ultradispersed crystalline phases of the C-N system

The results are given of the research on dynamic synthesis of crystalline covalent carbon nitride C3N4 in a hyperdynamic pulse stream of carbon electrical discharge plasma emanating into a space with a nitrogen atmosphere. The plasma source is a high-current pulse coaxial magnetoplasma accelerator with a graphite accelerator channel. The possibility to synthesize ultradispersed covalent carbon nitride has been shown.

Effect of Energy on Plasmodynamic Synthesis Product in the Carbon-Nitrogen System

Carbon nitride (CNx) powders were synthesized in the high-speed carbon electric discharge plasma jet flowing into the chamber filled with the nitrogen atmosphere at normal conditions. A coaxial magnetoplasma accelerator (CMPA) was used to generate the plasma flow. The CMPA was supplied from the pulse capacitive energy storage. Effect of input to the CMPA energy value on powders was studied by using several analytical methods (XRD, TEM, XPS). According to XRD with the increasing of input energy value the content of CNx in the product increased about 1.5 times. Its in a good accordance with the XPS data according to which the presence of nitrogen increased from 0.5 to 1.4 mass percent. Furthermore, the particles morphology was noticeable changed with the energy increasing. The obtained results revealed that by changing the energy parameters of the capacity energy storage its possible to influence on the product synthesized in the carbon-nitrogen system.

Electroerosive wear of the barrel of a coaxial hybrid magnetoplasma accelerator in the acceleration of solids

The main regularities of electroerosive wear of the barrel of a hybrid coaxial magnetoplasma accelerator in the acceleration of solids are studied. In order to significantly reduce the erosive wear of the barrel without changing the dynamics of solid projectiles, a system of discharge shunting in the acceleration channel was used. It is shown that the plasma structure of a high-current arc discharge is fountain-shaped and its bridge consists of numerous discrete conduction channels.

Direct dynamic synthesis of nanodispersed titanium nitride in a high-speed pulse electroerosion plasma jet

A possibility has been shown to produce nanodispersed TiN in a high-speed sputter-ion plasma jet generated by a coaxial magnetoplasma accelerator. The process is implemented in a short-time (∼10−3 s) operating cycle of the accelerator with titanium electrodes. The basic consumable is prepared by electroerosion from the surface of accelerating channel. Depending on the specific supplied energy dissipated in the channel powder particles can have both a spherical and an irregular form and sizes from 10 to 300 nm.

On the possibility of dynamic synthesis of ultradispersed crystalline phases of the B-C-N system in a hyperhigh-speed plasma jet

The results have been considered of the research on the possibility of cubic boron nitride (cBN) and cubic carbon nitride (c-C3N4) dynamic synthesis in hyperhigh-speed pulse jet of boron-carbon electric-discharge plasma, which flows into the space with a nitrogen medium. The source of the plasma is a high-current pulse coaxial magnetoplasma accelerator with a graphite accelerating channel. The data obtained have shown the possibility to synthesize ultradispersed cubic boron nitride and covalent carbon nitride.

Direct dynamic synthesis of nanodispersed phases of titanium oxides upon sputtering of electrodischarge titanium plasma into an air atmosphere

Experimental investigations of the possibility of directly synthesizing nanodispersed crystalline phases of titanium dioxides with rutile and anatase structures in a hypervelocity jet of electroerosion plasma generated by a coaxial magnetoplasma accelerator with titanium electrodes are presented. A powder product containing nanosized polymorphic phases of titanium dioxide with a spherical shape of particles has been manufactured.